Butyl benzoate as a dyeing assistant



United States Patent 2,880,050 BUTYL BENZOATE AS A DYEING ASSISTANT Fred Fortess, New Providence, and Jerome Rudy, Livingston, N.J., assignors to Celanese Corporation of America, New York, N.Y., a corporation of Delaware No Drawing. Application January 27, 1956 I Serial No. 561,952 7 13 Claims. (Cl. 8-55) This invention relates to dyeing and relates more particularly to dyeing with disperse cellulose acetate dyestuffs.

In dyeing with disperse cellulose acetate dyestuffs, it

is customary to bring the textile material to be dyed into contact with a heated bath comprising an aqueous dispersion of the dyestutf. This procedure is eminently satisfactory in the case of certain textile materialssuch as textile materials having a basis of the usual cellulose acetate of commerce (e.g. cellulose acetate having an acetyl value of 54-55%, calculated as combined acetic. acid). In treating this material the dyeing generally 2,880,050 Patented Mar. 31, 1959 4-bis(beta-hydroxyethyl) amino-2'-methyl-benzene; l-hydroxyethylamino 4 hydroxyethylamino 5 hydroxy- S-hydroxy anthraquinone; 4-nitrophenyl azo 4'-di-flhydroxyethylamino-2-acetaminobenzene; a mixture of 1,4-di(hydroxy-ethylamino)-5,8-dihydroxy anthraquinone and 1-amino-4-anilido anthraquinone; 1,5-dihydroxy-8- nitro-4-(meta-alpha-hydroxyethyl) anilido anthraquinone;

1,8 dihydroxy-4-(para-beta-hydroxyethyl) anilido5-nitro anthraquinone; l-amino-4-anilido anthraquinone; and 2,4-dinitro-6-chlorophenyl azo 4'-bis (hydroxyethyl) amino-2-acetylamino-5'-methoxy benzene. stuffs, as sold, are in the form of mixtures of a dispersing agent, such as sodium lignosulfonate or the sodium salt of formaldehyde-naphthalene sulfonic acid condensation product, with the actual dye material, and usually contakes place at a fairly rapid rate to produce any desired depth of shade, even when the disperse cellulose acetate dyestufi is of the high temperature slow dyeing type. However, when the same process is employed for the dyeing of a textile material having a basis of a celluloseester of low hydroxyl content (e.g. cellulose acetate 0 3 having an acetyl value of 59% or more, calculated as combined acetic acid) or a basis of a linear polyester of high melting point (e.g. polyethylene terephthalate or other carboxylic acid polyester melting above 200 (3., preferably above 230 'C.), the dyeing proceeds much more slowly and it is difficult to obtain deep shades.

It is an object of this invention to provide a new and improved process for the more rapid and complete dyeing of 'difiicultly dyeable textile materials, such as textile material having a basis of cellulose esters of low hydroxyl content or of linear polyesters of high melting point, with disperse cellulose acetate dyestuffs.

Another object of this invention is the provision of a novel aqueous dyebath comprising a disperse cellulose acetate dyestuff and a particularly effective dyeing assistant. 0 Other objects of this invention will be apparent from the following detailed description and claims. In this description and claims all proportions are by weight ii'nless otherwise indicated.

tile mater'ial having a basisof a cellulose ester of low hydroxyl content or of a polyester of high melting point, or of both, is colored by means of an aqueous dyebath tain about 30 to 45% of the actual dye material. Commercial dyestuffs of this type include those sold under the names Setacyl Blue G; Eastman Blue GLF; Interchemical Blue RLF-40 (Pr. 227); Celliton Blue AF (Pr. 227); Red -Y; -Celliton Blue Green BA (Pr. 229); Eastone Red ZB-GLF; Amacel Red 23;

Amacel Yellow CW; Eastone Red GLF; Amacel Rubine IX (Pr. 239); Scarlet III (Pr. 244); Interchemical Blue BGLF-40; Interchernical Blue-Green BALF-40 (Pr.'229); Amacel Violet Blue PSI, Lenra Blue RLS, Interchemical Blue GSF and Eastone Red N-GLF. All of these dyestufis are characterized by the fact that when applied to the ordinary cellulose ace tate textile materials, of 54 to 55% acetyl value, under certain standard conditions at 80 0, they will dye said textile materials in full shades, but when the same dyestuffs are applied to the same textile materials, under said standard conditions at a lower temperature, i.e. 60 C., the textile materials will be dyed to a substantially smaller extent, e.g. in shades whose depths are only about 65%;orless of the depths of the full shades. The standard, conditions mentioned above involve a treatment of 1 part by weight of the fabric in parts by weight of an aqueous dyebath comprising 0.5 gram per liter of soap,

e.g. sodium oleate, and 1% (based on the weight of the I fabric) of dyestufi.

containing a disperse cellulose acetate dyestufi in the I pre's'ehceof butyl benzoate. It is found that the presenceof the bnty1 benzoate greatly increases the rate of dyeing-and the degree of exhaustion of the dyebath. -1softhe butyl benzoate has a low degree of toxicity,

ean be' incorporated in the dyebath without disturbing the stability thereof,-and its use enables level dyeings of excellent crock resistance to beobtained.

. The dyestufis used inthe practice of this invention may h rming? disp rse cel ulose; acetate, dyestuffs known iQ'2h.e.-Iart;:.j "It.is preferred .to employthose dyestuffs whichtare 0f the: high temperature slowldyeing type since the-:useof these materials generally results in dyeings which have a very high degree of washfastness and usuanyare superior inresistance to gas fading, to light While the high temperature slow dyeing type of dis perse dyestutf is preferred it will be understood that'the process of this invention may also be used with the low -31 temperature or medium temperature types of disperse ---In"accordance with one aspect of this invention a texcellulose acetate dyestuffs. Examples of such dyestufis are 2-nitro 4-sulfonamido diphenylamine, p-nitrophenyl a'zo diethyl aniline and l-amino 4-hydroxy anthraquinone.

The proportion of butyl benzoate which is employed in the dyebath of this invention may be varied depending, for example, on the particular dyestuif employed and thedepth of shade desired. One suitable range is 5 to 30% based on .the weight of the textile material being dyed.

The butyl benzoate is preferably added to the dyebath in the form of an aqueous emulsion containing, for ex ample,- about 5 to 10% of the butyl benzoate and also containing an emulsifying agent. Best results are obtained by :the use of such emulsifying agents as Nekal NS These dyereaction product of polypropylene glycol with ethylene oxide having an ethylene oxide content of 40% and a molecular weight of about 3000), Emulphor ELA-719" (a polyoxyethylated castor oil containing 70-75% ethylene oxide groups), and Span 20" (sorbitan monolaurate). A suitable proportion of emulsifying agent is about to /2, preferably ,4 to V of the weight of the butyl benzoate. It is convenient to form the emulsion by first mixing the emulsifier and the butyl benzoate and then adding warm water while stirring.

Of the butyl benzoates, n-butyl benzoate is the preferred material, but other butyl benzoates, such as isobutyl benzoate, may be employed, alone or mixed with the n-butyl ester.

The butyl benzoate may, if desired, be mixed with other materials which act as assistants to increase the rate of dyeing. One such assistant is tripropyl phosphate, which is particularly useful in such processes as the dyeing of the cellulose ester of low hydroxyl content in a jig, wherein the liquor ratio (i.e. the ratio of the weight of dyebath to the weight of textile material) is low, e.g. 1:1 to 5:1, and the concentrations of dyestuff and butyl benzoate in the dyebath are relatively high. Thus, the replacement of part (e.g. to 90%, preferably 10 to 50%) of the butyl benzoate by an'equal amount of tripropyl phosphate in jig dyeing helps to solubilize the butyl benzoate and results in dyed cellulose ester textile materials which have even less tendency to crock. Another useful assistant which may be used to replace part (e.g. 10 to 50%) of the butyl benzoate in the dyeing of the cellulose ester of low hydroxyl content is a terpene, such as the mixture of monocyclic terpenes and p-cymene known as Solvenol #1.

The dyeing conditions such as the dyebath temperature, the pH of the dyebath, the proportion of dyestuff in the dyebath and the liquor ratio, may be varied'as desired. Thus the dyebath is preferably heated to a temperature of at least about 65 C. and, in order to accelerate the dyeing rate, the dyebath may be maintained, under superatmospheric pressure, at temperatures well above the normal boiling point of said bath, e.g. at temperatures of 100 to 140 C. With respect to the other dyeing conditions, a dyebath pH in the range of 6 to 8.5 has been found to give excellent results, while the proportion of dyestulf may be of the same order as that generally employed in dyebaths containing disperse cellulose acetate dyestuffs, e.g. about 0.1 to 6% (based on the weight of the textile material). For best results the dyebath should not be too dilute; for which dyeing, a. liquor ratio not above 50:1 and preferably about 30:1 to 12:1 is preferred. In jig dyeing, best results are obtained when the amount of butyl benzoate is not over 15%, preferably 10% or less, based on the Weight of the textile material.

The textile material may be dyed in any desired form, e.g. in the form of yarn, staple fiber, or fabric, which may be woven, non-woven, warp-knitted or circular-knitted. It may have a basis of a cellulose ester containing at most 0.29 alcoholic hydroxyl groups per anhydroglucose unit in the cellulose molecules thereof, such as highly esterified cellulose acetate, cellulose propionate, cellulose butyrate, cellulose acetate-formate, celulose acetate-propionate or cellulose acetate-butyrate. The preferred cellulose ester material is cellulose acetate of about 61% to 62.5% acetyl value, calculated as combined acetic acid. As previously stated, the textile material may have a basis of filaments of a linear polyester whose melting point is above 200' C., preferably above 230 C., for example, a glycol tercphthalate, such as polyethylene terephthalate, or a polyester of an aromatic hydroxy acid such as the homopolyester of 4-(B-hydroxyethoxy)-3-methy1 benzoic acid, alone or blended with filaments of the aforesaid cellulose ester.

After the dyeing of textile material it may be subjected to a heat-treatment operation, which, in the case of the cellulose ester of low hydroxyl content, has the effect of improving the washfastness and resistance to 'oxidativefading of the dye on the material and also improves the safe ironing temperature, resistance to shrinkage on pressing with moist steam and resistance to glazing of the textile material, as is now well known in the art. One suitable heat treatment involves passing the cellulose ester fabric through an infra-red heater or over heated plates or rollers, so that the surface of the fabric attains a temperature of, for example, 230 C.

The following examples are given to illustrate this invention further.

ExampleI A fabric woven of yarns of cellulose acetate of 61.5% acetyl value is immersed and agitated in an aqueous dyebath maintained at C. and containing 2%, based on the weight of the fabric, of a blue disperse dyestulf comprising 1,8-dihydroxy-4-(para-beta-hydroxyethyl) anilido-5-nitro anthraquinone), 10%, based on the weight of the fabric, of n-butyl benzoate, 1.2%, based on the weight of the fabric, of the emulsifier Nekal NS," and 2.5%, based on the weight of the fabric, of Igepon T-77 (comprising 77% of sodium N-methyl N-oleyl taurate and, the balance, sodium sulfate), the liquor ratio being 50:1. For comparative purposes, other pieces of the same fabric are dyed under identical conditions with dyebaths which are otherwise the same except that in one case (hereinafter termed the control dyebath") the butyl benzoate and Nekal NS are omitted, while in another case the butyl benzoate is replaced by an equal weight of another assistant, namely, methyl salicylate. The proportion of the dye absorbed from the dyebath is measured in each case. After one half hour of dyeing, the fabrics dyed in the presence of butyl benzoate and methyl salicylate have absorbed 81% and 16%, respectively, more dye than the fabric dyed in the control dyebath. After one hour of dyeing, the corresponding percentages are and 89%, respectively.

Example 11 Example I is repeated except that the fabric used is woven of yarns of polyethylene terephthalate (Dacron"). After one half hour the fabrics dyed in the presence of butyl benzoate and methyl salicylate have absorbed 330% and 286%, respectively more dye than the fabric dyed in the control dyebath. After one hour the corresponding percentages are 187% and respectively.

Example III Example IV Example III is repeated except that the fabric used is woven of yarns of polyethylene terephthalate (Dacron). After one half hour of dyeing the fabric dyed in the presence of butyl benzoate has absorbed 640% more dye than the fabric dyed in the control dyebath. After one hour the corresponding percentage is 607%.

Example V Example III is repeated except that the red dyestufi is replaced by the yellow disperse dyestutf Interchemical Acetate Yellow HDLF-40." After one half hour'of dyeing the fabric dyed in the presence of butyl benzoate has absorbed 67.2% more dye than the fabric dyed in the control dyebath. After one hour the correspondingpercentage is 23%.

Example VI Example III is repeated except that the fabric used is woven of yarns of polyethylene terephthalate (Dacron). After one half hour of dyeing the fabric dyed in the presence of butyl benzoate has absorbed 406% more dye than the fabric dyed in the control dyebath. After one hour the corresponding percentage is 413%.

Example VII Example I is repeated except that the fabric is made up of a blend of 50% of fibers of the cellulose acetate of 61.5% acetyl value and 50% of fibers of polyethylene terephthalate.

It is to be understood that the foregoing detailed description is merely given by way of illustration and that many variations may be made therein without departing from the spirit of our invention.

Having described our invention, what we desire to secure by Letters Patent is:

1. Process for the dyeing of a textile material having a basis of a cellulose ester having at most 0.29 hydroxyl group per anhydroglucose unit, which comprises bringing said textile material into contact with an aqueous bath containing a disperse cellulose acetate dyestuff in the presence of butyl benzoate as an assistant for increasing the rate of dyeing.

2. Process for the dyeing of a textile material having a basis of a linear polyester of melting point above 200 C. which comprises bringing said textile material into contact with an aqueous bath containing a disperse cellulose acetate dyestufi in the presence of butyl benzoate as an assistant for increasing the rate of dyeing.

3. Process for the dyeing of a textile material having .a basis of filaments of a cellulose ester having at most 0.29 hydroxyl group per anhydroglucose unit, and filaments of a linear polyester of melting point above 200 C. which comprises bringing said textile material into contact with an aqueous bath containing a disperse cellulose acetate dyestufi in the presence of butyl benzoate as an assistant for increasing the rate of dyeing.

4. Process for the dyeing of a textile material having a basis of cellulose acetate having an acetyl value of at least about 61% calculated as combined acetic acid, which comprises bringing said textile material into contact with an aqueous bath containing a disperse cellulose acetate dyestuff in the presence of butyl benzoate as an assistant for increasing the rate of dyeing.

5. Process for the dyeing of a textile material having a basis of a polyethylene terephthalate which comprises bringing said textile material into contact with an aqueous bath containing a disperse cellulose acetate dyestutf in the presence of butyl benzoate as an assistant for increasing the rate of dyeing.

6. Process for the dyeing of a textile material having a basis of filaments of cellulose acetate having an acetyl value of at least about 61% calculated as combined acetic acid and filaments of polyethylene terephthalate which comprises bringing said textile material into contact with an aqueous bath containing a disperse cellulose acetate dyestufl in the presence of butyl benzoate as an assistant for increasing the rate of dyeing.

7. Process as set forth in claim 4 in which said disperse cellulose acetate dyestufi is of the high temperature slow dyeing type and the dyebath is heated to a temperature of at least 65 C. and contains about 5 to 30%, based on the weight of the textile material, of butyl benzoate.

8. Process as set forth in claim 5 in which said disperse cellulose acetate dyestufi is of the high temperature slow dyeing type and the dyebath is heated to a temperature of at least 65 C. and contains about 5 to 30%, based on the weight of the textile material, of butyl benzoate.

9. Process for the dyeing of a textile material having a basis of cellulose acetate having an acetyl value of at least about 61% calculated as combined acetic acid, which comprises bringing said textile material into contact with an aqueous bath containing a disperse cellulose acetate dyestufi in the presence of butyl benzoate as an assistant for increasing the rate of dyeing and tripropyl phosphate.

10. Process for the dyeing of a textile material having a basis of cellulose acetate having an acetyl value of at least about 61% calculated as combined acetic acid, which comprises bringing said textile material into contact with an aqueous bath containing a disperse cellulose acetate dyestufi in the presence of butyl benzoate as an assistant for increasing the rate of dyeing and a terpene.

11. A dyebath comprising an aqueous medium containing a disperse cellulose acetate dyestutf and butyl benzoate as an assistant for increasing the rate of dyeing.

12. A dyebath comprising an aqueous medium containing a disperse cellulose acetate dyestufi and butyl benzoate as an assistant for increasing the rate of dyeing and tri-n-propyl phosphate.

13. A dyebath comprising an aqueous medium containing a disperse cellulose acetate dyestulf and butyl benzoate as an assistant for increasing the rate of dyeing and a terpene.

References Cited in the file of this patent UNITED STATES PATENTS 2,288,685 Croft July 7, 1942 2,524,811 Koberlein Oct. 10, 1950 2,646,339 Ward July 21, 1953 2,754,171 Salvin July 10, 1956 FOREIGN PATENTS 313,072 Great Britain Aug. 28, 1930 OTHER REFERENCES 

6. PROCESS FOR THE DYEING OF A TEXTILE MATERIAL HAVING A BASIS OF FILAMENTS OF CELLULOSE ACETATE HAVING AN ACETYL VALUE OF AT LEAST ABOUT 61% CALCULATED AS COMBINED ACETIC ACID AND FILAMENTS OF POLYETHLENE TEREPHTHALATE WHICH COMPRISES BRINGING SAID TEXTILE MATERIAL INTO CONTACT WITH AN AQUEOUS BATH CONTAINING A DISPERSE CELLULOSE ACETATE DYESTUFF IN THE PRESENCE OF BUTYL BENZOATE AS AN ASSISTANT FOR INCREASING THE RATE OF DYEING. 